This invention relates to pads which close the tone holes of woodwind musical instruments including but not limited to flutes, saxophones, bassoons, oboes, piccolos and clarinets.
The predominant pad now used is a bladder pad formed of a bottom disc of cardboard and an upper disc of felt. A covering of one to three layers of a thin membranous material called the "bladder skin" covers the felt disc, is wrapped around the edges of both discs and is bonded to the cardboard disc. Another common pad is the leather pad which is similar to the bladder pad but in lieu of a "bladder skin" has an enveloping layer of thin, soft leather. The bladder pads and leather pads perform well but are readily damaged by water, oil, insects and metal polishing compounds.
Sheet cork is also used for pads, particularly in oboes and piccolos. These have the advantage of producing crisp transitions between notes, but have the disadvantage of producing a conspicuous click when the pad is closed against the tone hole. These pads are more durable than bladder pads or leather pads, but their installation is more difficult.
There have been many proposals for various types of elastomer pads formed from natural or synthetic organic resins such as natural rubber or polyvinyl chloride. These pads have not been widely accepted. Some elastomer pads become sticky due to their compounding with excessive amounts of plasticisers. Some elastomer pads discolor, age, undergo a change in texture or compress excessively to give the performer a spongy feel. Others have a corrosive effect on metallic instruments.
The present invention provides an elastomer pad which avoids the disadvantages described above, and provides for long life, a good "feel" to the musician, substantially noiseless operation and an aversion to sticking to the tone hole. This is achieved by the selection of an elastomer, preferably of a silicone rubber, having a compression set which is no greater than about 5% after being compressed to 75% of its original thickness at room temperature for 22 hours and then released for one-half hour.
Preferably, the woodwind pad of the invention includes such an elastomer disc and a backing disc, the edges of the elastomer disc being tapered outwardly in the direction of the tone hole to minimize the surface area facing the pad cup and to maximize the surface facing the tone hole. Also, it is preferred that the elastomer disc have a durometer of about 20-60 on the Shore A scale.
For a more complete understanding of the invention, a preferred embodiment is shown in the accompanying drawings and described in the following description.